diff --git a/Data/String/ToString.hs b/Data/String/ToString.hs
--- a/Data/String/ToString.hs
+++ b/Data/String/ToString.hs
@@ -22,7 +22,8 @@
 
 -- | Class of string-like types that can be converted to 'String's.
 --
--- Ensure that instances of this class obey the 'prop_fromToString' law.
+-- Ensure that types that have an instance for this class and also have an
+-- instance for 'IsString' obey the 'prop_fromToString' law.
 class ToString s where
     -- | Convert a string-like type to a 'String'.
     toString :: s -> String
@@ -31,7 +32,10 @@
     toString = id
 
 instance ToString Char where
-    toString = (:[])
+    toString = (: [])
+
+instance ToString ShowS where
+    toString = ($ [])
 
 -- | General coercion between string-like types.
 --
diff --git a/to-string-class.cabal b/to-string-class.cabal
--- a/to-string-class.cabal
+++ b/to-string-class.cabal
@@ -1,11 +1,11 @@
 Name:                   to-string-class
-Version:                0.1.1
+Version:                0.1.2
 Synopsis:               Converting string-like types to Strings.
 Description:            This library provides the class:
                         .
                         class ToString s where toString :: s -> String
                         .
-                        Instances for String and Char are provided.
+                        Instances for String, Char and ShowS are provided.
                         For other instances see the package:
                         .
                         <http://hackage.haskell.org/package/to-string-instances>